In recent years, printers using an inkjet recording method, such as inkjet printers and inkjet plotters, have been widely used in not only printers for general consumers but also industrial purposes, such as formation of an electronic circuit, manufacturing of a color filter for a liquid crystal display, and manufacturing of an organic EL display.
Such printer using the inkjet recording method is provided with a liquid discharge head for discharging liquid as a printing head. For this type of printing head, a thermal method and piezoelectric method are commonly known. In the thermal method, a heater as a pressurizing means is provided in an ink passage filled with ink, the ink is heated and boiled with the heater to generate air bubbles in the ink passage, and the air bubbles pressurizes the ink, thereby causing the ink as an ink droplet to discharge from an ink discharge hole. In the piezoelectric method, a part of a wall of an ink passage filled with ink is bent and displaced by a displacing element to mechanically pressurize the ink in the ink passage, thereby causing the ink as an ink droplet to discharge from the ink discharge hole.
The liquid discharge head can employ either serial method or line method. In the serial method, recording is carried out while the liquid discharge head is moved in a direction (main scanning direction) orthogonal to a transport direction (sub scanning direction) of a recording medium. In the line method, recording is carried out on a recording medium transported in a sub scanning direction in a state where a liquid discharge head being longer in a main scanning direction than a recording medium is fixed. The line method has an advantage of permitting high speed recording because unlike the serial method, there is no need to move the liquid discharge head.
A known liquid discharge head includes, in addition to a liquid discharge head body having a piezoelectric actuator for pressurizing liquid so as to discharge the liquid from a passage member having a discharge hole and the discharge hole, a reservoir for temporarily storing the liquid so as to stably supply the liquid to the liquid discharge head body (for example, refer to Patent document 1). In the liquid discharge head, the reservoir is stacked on the side of the long liquid discharge head on which the piezoelectric actuator is bonded, and an FPC (Flexible Printed Circuit) for transmitting a signal to drive the piezoelectric actuator is pulled out from between the liquid discharge head and the reservoir.
In a reservoir passage of a reservoir of an accumulating discharge head described in Patent document 2, liquid introduced from an end of the long liquid discharge head is sent to the liquid discharge head body at the center of the liquid discharge head.